Energy storing spring joint

ABSTRACT

An energy storing spring joint (100) for use between two parts movable with respect to each other and joined by the energy storing spring joint is capable of storing energy in such a way that energy is stored in a displacement path and is released in very precise and predetermined manner, with a variable force over the path of displacement, when the parts move in the opposite or backward direction in the path of displacement. At least one energy storing member (50) or at least two energy storing members (50) connected sequentially or at least two different energy storing members (50) connected in parallel are mounted in or on the energy storing spring joint (100) and may be moved by or loaded with energy when one of both parts (30, 40) is moved relative to the other part. The energy storing member(s) (50) may be locked against releasing their energy.

This is a division of United States patent application Ser. No.08/500,939, filed Jul. 21, 1995 now U.S. Pat. No. 5,634,241, which is aU.S. national phase filing of PCT application No. PCT/EP94/00157, filedJan. 21, 1994 which is based on German application No. G 9300903.2,filed Jan. 23, 1993.

BACKGROUND AND SUMMARY OF THE INVENTION

The energy storing spring joint can be used wherever two parts can bemoved in a rotary motion relative to each other. This can involvesituations where one part is fixed or where both parts rotate inopposite directions or at different speeds with respect to each other.

The invention concerns an energy storing spring joint for storingenergy, which is to be used between two parts which are moveablerelative to each other, and which are joined by the energy storingspring joint.

Devices for storing energy, work and power are known in the most variedembodiments. Thus, spring mechanisms for clocks or spring driven motorsfor toys are also known. With these devices, for example, the energywhich is added to the energy storing device by applying a force to itcan be stored and once again released.

These known energy storing devices most often release the energycontinuously or with decreasing intensity. However, there are examplesof applications, where it is desirable to use an energy storing device,which delivers the energy on a predetermined basis and/or according todemand at varying levels of intensity as a function of its displacementor as a function of time.

Hinges for vehicles represent an especially suitable area ofapplication.

Trailers of trucks or in the area of agricultural equipment includeloading gates, which are linked to the trailer by means of simplehinges. The hinges are frequently installed at the lower edge of theloading gate, so that when they are manually opened or closed, aconsiderable physical effort must sometimes be made to move the gate,and during this effort the required application of force is naturallygreatest, when the angle between the loading gate and a vertical planeis 90°.

It is, therefore, the objective of the invention to create an energystoring spring joint of the type initially described, which can storeenergy in such a manner, that it is possible to store energy during amovement along a given path in such a way, that in the case of amovement in an opposite direction or during a reversal of the motion,the energy can be released in a very definite, predetermined manneralong the path of motion, and where the amount of energy released can bevaried as a function of displacement.

The objective is achieved by the characteristics described in claim 1.

An essential idea on which this objective is based, is that the forcesbeing generated during the relative movement of two parts with respectto each other, such as weight forces, forces due to the kinetic energyto be absorbed etc., must be counteracted and stored in the energystoring device in the form of potential energy. In order to be able torelease the energy subsequently on a continuous basis, it iscontemplated that it will be stored in at least one energy storingdevice or in two energy storing devices, which are independent of eachother. These devices can be charged with potential energy one after theother, or energy storing devices, which differ from each other may beemployed, in which energy is accumulated in parallel. Both systems canalso be combined. It is important that an energy release, for example inorder to support the movement of the parts toward each other, can befacilitated while motion takes place, and in particular, in accordancewith the invention, on the basis of a definitive, predeterminableprocess of the release of energy. This means that, for example, at thestart of the movement only a small amount of energy is being taken fromthe energy storing device or devices, or that an especially large amountof energy is extracted from a force, and that subsequently a removal ofenergy occurs on a different level of energy, which may, under certaincircumstances, change once again.

Preferably, it is contemplated that the energy storing devices are madeof springs. According to the invention, these springs are eitherconnected in series in such a manner that in each of them, one after theother, the entire possible amount of energy is being stored, while theenergized springs are kept in their energized condition or undertension, as the case may be, until all the springs have been energized.A further basic idea consists in preventing or blocking the energystoring device or devices against a release of their energy in such amanner, that a further movement of the two parts toward each other isstill possible. It Is, therefore, possible to provide a still furthermovement of the parts, during which no further storage of energy takesplace. Then, during the return movement of the parts, the discharge ofenergy takes place at a time that can be predetermined and/or at pointsalong the path, which can be determined in advance.

In this context, it can be arranged that at least two springs havedifferent spring constants or that one different spring has propertiessuch as a progressive or degressive change of the spring constants alongthe path of motion of the spring, and/or that the energy storingdevices, during the movement of the parts toward each other, can all beenergized along the entire path of movement, and that they can all bede-energized along a combined path of movement in the oppositedirection. For this purpose, the springs may be constructed as tensionsprings, compression springs, spiral springs or torsional springs, andthey can be designed and selectively positioned in such a manner thatthey can be adjusted with regard to their initial tension.

A very particular objective consists in creating an energy storingspring joint, which can store energy in such a manner, that the openingand closing of, for example, loading gates can be assisted in such away, that as a result only minimal forces need to be applied, while theextent of the assistance can be varied.

This objective is achieved by the characteristics identified in claim 7.

For this purpose, it is contemplated, in accordance with the invention,to create a spiral spring system, which is equipped with several spiralsprings, which have varying spring constants, and which store the energybeing generated during the lowering of the gate, so that this energy canbe utilized to assist while the gate is being raised, and for whichsystem an area of use is found wherever two parts, which are connectedto each other, must be pivoted relative to each other while a force isbeing applied. However, it would be advantageous if the force of gravitycould be utilized in one of the directions of rotary motion.

Such a spiral spring system for, for example, a hinge for a gate,consists of a cover tube, which is dosed at one end and whichconstitutes an enclosure sleeve, which has been provided with afastening means, which is attached to the gate of the trailer.

In the cover tube, which forms an enclosure sleeve, the hinge of thetrailer contains several spiral springs, through which a shaft isextended, which is attached to the trailer. The spiral springs are alsoattached to the shaft, and they are supported by the impact member ofthe catchment device at the inside of the cover tube. Between the covertube, which forms the enclosure sleeve, and the spiral spring, there isa guide sleeve which is rigidly attached to the trailer and whichcontains guide slots and functions in such a way that one free end of aspiral spring is always being guided in a guide slot in such a mannerthat it can be picked up by a cam of the catchment device. If the gateis now operated, the cover tube is rotated and, as a rule, places thespiral springs under tension, one after the other, due to the action ofthe catchment device, the free ends of which (the spiral springs) thusare induced to continue to move through the guide slots of the guidesleeve, and they do so specifically by moving along the main portion ofthe guide slot, which is approximately perpendicular to the shaft Theend portions of the guide slots proceed approximately parallel to theshaft. By being displaced into the end section, the end of the spiralspring is guided away from the region of the catchment device and isplaced in a storage position, in which it cannot be further tensioned,but in which the current tension can be maintained. The catchmentdevice, which has the shape of a bead and is disposed in the form of apartial circumferential ring on the inside of the enclosure sleeve, thenslides, along with the impact member, past the end of the spiral spring,which has been pushed away toward the end portion of the guide slot, andthe free end is kept in its position, while it slides along a lateralglide path of the catchment device, even if the enclosure sleeve isrotated further. If this motion is carried out in the oppositedirection, i.e the gate is being closed, then the spring slides out ofits storage position, after the impact portion of the catchment devicehas been rotated past the end of the spiral spring while it was beingturned back, because it pushes through the space, which has beengenerated in the end region, into the region of the cam of the catchmentdevice, and then pushes against the impact portion of the catchmentdevice, by which action the closing process is assisted. The springconstant and the disposition of the cams and the slots are chosen insuch a way, that they are adapted to the energy use pattern during theclosing of the gate.

In this context, it can also be arranged that the catchment deviceextends through 360° or more an the inside of the cover tube. In thiscase, the bead must not be positioned at a right angle with respect tothe shaft, but must proceed in a spiral pattern in the form of a kind ofbead-like thread, in which case the pitch of the bead-like thread andthe length of the end portion of the guide slot must be adjusted to eachother in such a manner, that when the end of the bead of the catchmentdevice has been reached, the free end of the spring is located in theend portion of the end section.

The impact surface of the impact member is positioned at an anglerelative to the longitudinal extension of the catchment device in such away, that the free end of the spiral spring positions itself in such amanner that it positions itself against a wall of the guide slot at thesame time that it is forced by it due to the interaction with the impactsurface, into the end region of the guide slot.

This system of spiral springs can be used in many different ways in allareas, in which spiral springs are needed, while, by the selection ofthe spring constants and the positioning of the cams of the catchmentdevice, or as the case may be, the guide slots, an individual adaptationis always possible.

In this context, it is especially advantageous, that the direction ofeffective action for the storage of energy in both directions of motioncan be accommodated by an appropriate placement of the guide slots andthe spiral springs.

By selecting and employing springs with different spring constants, andby choosing spring constants which change along the path of tensioning,it becomes also possible to absorb different forces, for example varyingweight forces, which may be generated along the rotary path of motion ofa hinge, so that an easy moveability can be achieved.

Further advantageous embodiments are characterized in the sub-claims.

BRIEF DESCRIPTION OF THE DRAWINGS

An example embodying the invention is explained below in greater detailby referring to the drawings. They show the following:

FIG. 1 In a partial section of a side view, a spiral spring system inaccordance with the invention is shown in the form of the hinge of agate.

FIG. 2 In a cross-section, a spiral spring system in accordance with theinvention is shown in the form of the hinge of a gate.

FIG. 3 A partial section of a side view of a detail of a spiral springwith guide slots and catchment devices is shown in a state of slackness,and

FIG. 4 a partially sectioned side view of a detail of the spiral springwith a guide slot and a catchment device is shown In a tensioned state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a spiral spring system in accordance with the Invention inthe form of a gate hinge 100, e.g. a trailer for trucks, in which thecams 10a-e of the catchment device for spiral springs 11a-e are shown ina single plane for the sake of simplicity and ease of visualization.

The gate hinge 100 contains a shaft 12, which is attached to a part 30,e.g. the trailer, which is only hinted at in the drawing, and whichshaft is extended through several spiral springs 11a-e, and to whichshaft the spiral springs 11a-e are attached at one end. The free ends13a-e of the spiral springs 11a-e are extended through the guide slots14a-e of a guide sleeve 15, where the guide sleeve 15 is immovable withrespect to shaft 12, because both are joined to each other by afastening means 12a, which is also used for attaching it to the trailer.The shaft 12, the spiral springs 11a-e and the guide sleeve 15 arelocated in an enclosure sleeve 16, one side of which is closed off. Theenclosure sleeve is attached to a second part 40, e.g. the gate of thetrailer,

At its closed side 16a, there are located on the inside 17 of theenclosure sleeve 16 a guide portion 18 for the shaft 12 and a guide ring19 for the guide tube 15. On the inside 17 of the enclosure sleeve 16,there are located the catchment devices 10a-e. which may also beconstructed as cams and which exert a force against the free ends 13a-eof the spiral springs 11a-e, when the enclosure sleeve 16 goes through aturning motion relative to the shaft 12.

In FIG. 2, the gate hinge 100 is shown as a cross-section, in order todemonstrate a possible arrangement of the catchment devices 10a-e.

FIG. 3 and FIG. 4 explain the modus operandi, or as the case may be, thestorage of the spring energy by means of the particular interaction ofthe catchment devices 10a-e and the guide slots 14a-e. The guide slots14a-e proceed at a right angle to the shaft 12 in the guide sleeve 15,while their end portion terminates by being bent to the side at nearly aright angle. The straight section of the guide slots 14a-e extends alonga path congruent to that of the catchment devices 10a-e for the spiralspring 11a-e, while the end region serves to guide the free end of thespiral spring 11a-e away from the impact area of the cam of thecatchment device 10a-e. When the shaft 12 is rotated relative to theenclosure sleeve 16 in a direction X, each catchment device 10a-e exertsa force against one end of a spiral spring 11a-e, which causes it (thespiral spring) to be tensioned. While this takes place, the end of thespiral spring moves along the straight section of the guide slot and theangled end is rotated into a position (FIG. 4), in which the springcannot release the energy again, because the spiral spring 11a-e isfirmly held in this position by the guide slot 14a-e and by the outsideof the catchment device 10a-e, which moves around the inside 17 of theenclosure sleeve 16.

It is further contemplated, that the catchment devices (10a-e) areconstructed as bead-like or fin-like partial rings or threaded rings,which are extended on the inside (17) of the enclosure sleeve (16), andeach of which is equipped with an impact member (20) for exerting aforce on the free end (13a-e) of a spiral spring (11a-e) as well as witha lateral glide path (21). It is possible to use the same basicstructure and, in the place of each catchment device, to generate aguide surface in the enclosure sleeve in the form of a guide slot insuch a way, that an appropriate guidance of the free end of the springis accomplished. It is also possible to set up this arrangement in akinematic reversal. For this, the springs can be permanently supportedin the enclosure sleeve, the angled free end can be extended through theguide slot in the guide sleeve, and the end region can be disposed inthe area of a catchment device or guide slot, which is formed on theshaft. Preferably, it is also possible to build the joint with only onesuitably constructed spring.

I claim:
 1. An energy storing device (100) for connecting two parts (30,40) which are movable with respect to each other comprising a base part(12) connected to one of said two parts (30, 40), an enclosure part (16)connected to the other of said two parts, which are connected by atleast one energy storing means (50), wherein a free end of said energystoring means can be selectively caught and released by a catchmentdevice associated with one of the enclosure part (16) and the base part(12) when one of said two parts (30, 40) is moved relative to the otherpart, and a guiding means (15) connected to one of the enclosure part(16) and the base part (12) for guiding the free end of said energystoring means (50), characterized in that the guiding means (15)comprises a guide surface (14a-14e) for guiding the free end interactingwith the catchment device (20) in such a manner that a predeterminedforce over the path of displacement is varied as one of said two parts(30, 40) is moved relative to the other part.